A software upgrade under the NHS's National Programme for IT (NPfIT) has led to hundreds of incorrect duplicate patient records being created every day at NHS sites in Greater Manchester.
A team has been formed to prevent patient data being lost. The emergency action raises questions about how well NPfIT systems are being tested before going live.
The affected systems are creating up to 400 duplicate patient records a day. Internal documents show that the duplicates have been created on the assumption that a patient does not already have a record - even if they do.
If these duplicates are left in place, it could lead to clinicians seeing patients without access to important medical history.
To stop this happening, the actual patient record must be merged with the duplicates. But if a backlog of unmerged records builds up, hospital record libraries could send clinicians the wrong patient file based on the duplicate record, which could pose a clinical safety risk.
The internal documents warn that merging records is creating significant extra work. And the merged files may later need to be unscrambled to maintain data integrity on patient administration systems.
Problems arose after Maintenance Release 1 of the IPM patient administration system was rolled out by NPfIT local service provider CSC and its subcontractor iSoft.
The upgrade, over the weekend of 21 and 22 April, led to up to 400 duplicated records being created each day for patients who had hospital appointments made using the Choose and Book NPfIT system.
Computer Weekly has received other internal documents which show that the incident in Greater Manchester is not isolated. There have been about 200 "major incidents" at NHS hospitals in the four months to the end of January 2007.
Dozens are in the highest "severity one" classification and some have affected NHS sites across England. Pacs digital systems and radiology information systems are among those to have suffered failures.
The problems undermine the position taken last month by health minister Lord Hunt that a Public Accounts Committee report on the NPfIT was based on information that was out of date. The latest incidents all occurred in the past seven months.
CSC and Connecting for Health, which runs the NPfIT, said of the problems in Manchester, "Although comprehensive testing is undertaken prior to upgrades, it is not unusual for these kinds of upgrades to identify teething problems in the early stages following implementation."
They said an interim fix was in place and CSC was developing a permanent fix that would be available within three weeks.
The Health Committee of the House of Commons began its inquiry into aspects of the NPfIT on 26 April 2007 but its narrow terms of reference exclude looking into the threats to healthcare of troubled NPfIT go-lives.